1.5- Cyclooctadiene rhodium complexes

Catalytic Asymmetric Hydroboration. The hydroboration of olefins with catecholborane (an achiral hydroborating agent) is cataly2ed by cationic rhodium complexes with enantiomericaHy pure phosphines, eg, [Rh(cod)2]BE4BINAP, where cod is 1,5-cyclooctadiene and BINAP is... 

Replacements of ferrocene-substituted p-diketone ligands, p-dik, in cyclooctadiene-rhodium(I) complexes [Rh(p-dik)(cod)] by 1,10-phenan-throline are characterized by large negative activation entropies, indicating the operation of the expected associative mechanism, although the... 

Chiral bis(phosphinites) derived from (2/J,51 )-2,5-di(hydroxymethyl)tetrahydrothiophene have been prepared (Equation 73). These ligands have been used in the synthesis of rhodium complexes from Rh(COD)2X (COD = cyclooctadiene X = OTf, SbF6) and tested in the asymmetric hydrogenation of methyl a-acetamidocinna-mate. A maximum of 55% enantioselectivity was observed <19980M4976>. 

In an ethanol solution of RhCl3, cis,irons-1,5-cyclodecadiene is converted to its cts,cis-l,6-isomer with subsequent formation of the dimeric rhodium complex [(l,6-CioHie)RhCl]2 which can also be prepared by direct interaction of the 1,6-olefin with RhCl3 in ethanol (579, 582). Spectral evidence suggests a configuration (192) much like that of the 1,5-cyclooctadiene complex with the 1,6-CioHie rings in a boat conformation. 

QH P, Phosphine, dimethylphenyl-, iron complex, 26 61 molybdenum complex, 27 11 osmium complex, 27 27 osmium-rhodium complex, 27 29 osmium-zirconium complex, 27 27 ruthenium complex, 26 273 CkH,2, 1,5-Cyclooctadiene, iridium complex, 26 122, 27 23 osmium-rhodium complex, 27 29 ruthenium complexes, 26 69-72, 253-256 CbH 20,PS, 2-Butenedioic acid, 2-(dimeth-ylphosphinothioyl)-, dimethyl ester, manganese complex, 26 163 ChH,4, Cyclooctene, platinum complex,... 

The first place in catalytic hydrogenation nowadays is taken by Rh or Ru complexes of BINAP. This ligand has axial chirality as the naphthalene rings cannot rotate past each other. These compounds were developed by Noyori, who with Knowles and Sharpless received the 2001 Nobel prize for their contributions to asymmetric synthesis. BINAP 20 is usually made from BINOL 19 and either 19 or 20 can be resolved. Rhodium complexes similar to those we have met include a molecule of cyclooctadiene and, as these are Rh(I) compounds, a counterion, often triflate 21. Both enantiomers of BINAP are available commercially.8... 

C4H,o, 1,3,5-Cyclooctatriene, ruthenium complex, 22 178 CgHl2, 1,5-Cyclooctadiene, iridium complexes, 23 127 rhodium complex, 23 127, 129 ruthenium complex, 22 178 C8H]4, Cyclooctene, iridium complex, 21 102 CsH16, Cyclooctane, boron complex, 22 199... 

In contrast, the iridium complex XLVb is more reactive than the corresponding rhodium complex XLVa. Furthermore, the reaction rates in this reaction are independent of the diene (cyclooctadiene isoprene 2,3-dimethylbutadiene) . 

Tributyltin hydride adds to terminal acetylenes in the presence of triethylborane to give mixtures of E)- and (Z)- alkenes, in which the tin atom is attached to C(l), e.g. equation 40215,216 reverse regiochemistry is observed in the reaction of tributylstannane with terminal acetylenes in the presence of rhodium complexes, e.g. [RhCl (1,5-cyclooctadiene)]2, to yield exclusively the adducts 297. ... 

Originally discovered by Reppe and co-workers, hydroaminomethylation of olefins has attracted attention as an economical, one-pot synthesis of amines. Alper and co-workers have demonstrated that zwitterionic rhodium complex [Rh (q -cyclooctadiene)(q -CgH5BPh3)-] 74 is an excellent catalyst for hydroaminomethylation of phenylalkenes 75 to afford the corresponding branched methylated amines 76 with high regioselectivity (Scheme 22) [42]. 

Rh02[As(CBH6)3]i +A"(A" = PFe" or ClOa"). This rhodium dioxygen complex is prepared by reaction of chloro(4,5-cyclooctadiene)rhodium(I) dimer (Strem) with triphenylarsine in the presence of oxygen (air) followed by addition of NHaPFe or LiClOa. ... 

Rhodium(I) bis(l,5-cyclooctadiene) tetrafluoroborate complex [bis(l,5-cyclooctadiene)rhodium(I) tertra-... 

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